I have found fix for crash-to-desktop in Prepar3D v5 with NGXu. If you open 2D panel pop ups in virtual cockpit , simulator crash.
Fix:
1. Go to "SimObjects\Airplanes\PMDG 737-800NGXu\panel" open "panel.cfg" with editor text .
2. Find with text "zorder = number" and replace all to "zorder = 99"
3. Save editor text then start simulation .